“It’s going to get us into the green category without costing the customer more,” Duschene said.

Duschene’s company appears to be the first in Montana, Wyoming or South Dakota to convert all its mowers to propane, a move that has been growing in popularity on the coasts — and particularly in smog-stricken California — over the last few years, despite its relative newness for use in mowers, said Tim Shea, account manager for AmeriGas.

Duschene made the decision at the beginning of this winter to convert his mowers, looking for “better ways to not pollute,” he said.

According to Shea, one of Duschene’s industrial gas-powered mowers releases roughly the equivalent in emissions of 40 late-model cars each hour before the conversion.

Converting to propane reduces production of harmful greenhouse gases by roughly 30 percent and reduces cancer-causing emissions by up to 96 percent, Shea said.

Propane’s low carbon content — responsible for the reduction in pollutants — will also reduce the frequency of oil changes needed on Duschene’s mowers and could double engine life, he said.

Propane is also generally $1 or more less per gallon than gasoline, and the conversion reduced the noise output of the machines as well, Shea said. The mowers, meanwhile, should see about the same fuel economy as they did with gasoline, Duschene added.

Duschene spent about $5,000 on the conversion kits, and his mechanic installed them in about three days, he said. But the overall cost came in closer to $35,000 as Duschene bought several new mowers to help get the most savings out of the conversion (mowers with less than 200 hours will see the biggest benefit from propane power), he said.

The choice does equal a cost savings over time, but it was inspired more for the reduction in harmful emissions and the potential to spread the word about the technology, Duschene said.

“It’s just a responsible choice for us,” he said. “I hope it really changes the view for how other companies do things.”

Duschene said he also plans to convert all his blowers and trimmers to propane as soon as the technology is available to do so, and he hopes to later convert all his vehicles to propane as well.